This invention relates to containers for bulk materials, and particularly to large containers of the kind used for handling and storage of food and chemical products. In the food processing industry, products such as poultry, meat and fruit are handled, stored and shipped in containers having capacities ranging from approximately 50 to 250 gallons of liquid. These containers are made of various materials, including paperboard, galvanized steel, stainless steel, and plastic. Usually, the containers are open-topped vessels, having a bottom and four upwardly extending sides, and being closable at the top by a separate cover. They are used not only by food processors, but also in agriculture, and in the pharmaceutical, chemical and petro-chemical industries for handling and storing a wide range of products.
The containers are large in size, and the term "large" as used herein will be understood to refer to a size of a container such that, when filled with a product, cannot be easily carried manually by a single person. Normally, fork lifts or pallet jacks are used to transport these large containers. Unless the container itself is provided with openings for the insertion of fork lift or pallet jack tines, a separate pallet is required. Tanks can be provided with legs or openings to accommodate lifting mechanisms. Constructing such legs or openings adds much to the complexity and cost of paperboard and steel containers. In the case of plastic containers, legs suitable to accommodate fork lift tines can be readily provided in the process of molding the container without greatly increasing the cost of the container. However, unless the legs are solid, their interiors will form a number of narrow pockets open to the interior of the main body of the container. Such pockets are objectionable especially in food processing, because they tend to collect food particles, and are difficult to clean. Solid legs, on the other hand, are more difficult to mold, and not only waste plastic, but add to the weight of the container without materially improving its strength.